亚硝基氮胁迫下WSSV对凡纳滨对虾致病性研究  

Study on the pathogenicity of WSSV to the cultured shrimp Litopenaeus vannamei under nitrite stress

作　　者：方金龙[1,2] 王元[1] 李新苍[1] 周俊芳[1] 陈甜甜[1,2] 房文红[1] 

机构地区：[1]中国水产科学研究院东海水产研究所,农业部海洋与河口渔业资源及生态重点开放实验室,上海200090 [2]上海海洋大学水产与生命学院,上海201306

出　　处：《东北农业大学学报》2016年第9期39-45,共7页Journal of Northeast Agricultural University

基　　金：上海市虾类产业技术体系建设项目(沪农科产字(2014)第5号);上海市科技兴农重点攻关项目(沪农科攻字(2013)第6-4号)

摘　　要：为评价养殖水环境中亚硝基氮(NO_2^--N)对凡纳滨对虾(Litopenaeus vannamei)危害性,开展NO_2^--N胁迫对凡纳滨对虾感染白斑综合征病毒(WSSV)后的死亡率、WSSV在患病对虾体内增殖速率和对虾主要免疫相关酶活性影响研究。试验设置NO_2^--N胁迫浓度为6.68 mg·L^(-1),分别注射10^(-4)和10^(-5)稀释度的WSSV提取液,结果显示,胁迫下感染10-4WSSV的凡纳滨对虾144 h死亡率达90.00%,显著高于无胁迫组(60.00%),相同试验条件下高浓度病毒感染组死亡率高于低浓度组。对虾鳃组织WSSV荧光定量PCR检测结果显示,NO_2^--N胁迫下凡纳滨对虾鳃组织内WSSV增殖加快,感染48 h后10-4攻毒浓度胁迫组病毒量是无胁迫组1.33倍,72 h时病毒量达到无胁迫组2.00倍。此外,免疫相关酶活性结果显示,NO_2^--N浓度突变导致对虾血清中酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)活性先升后降。由此可见,NO_2^--N胁迫会加快WSSV在患病凡纳滨对虾体内增殖,导致高死亡率,这可能是胁迫造成对虾免疫相关酶活性降低和抗病原感染能力下降所致。In order to evaluate the harmfulness of nitrite on white pacific shrimp, Litopenaeus vannamei, this study was conducted to determine the effects of nitdte （NO2-N） on mortality of shdmp infected with WSSV, WSSV proliferation in infected shrimp and activity of immune-related enzymes in serum. The experiment consisted of treatments infected with WSSV extract of 10^-4 and 10^-4 dilution under the stress of 6.66 mg· L^-1 NO2-N, and there were the relative groups without stress as control. The results showed that the mortality of the treatment of stress-10^-4 WSSV reached 90.00% at 144 h, significantly higher than control of stress-free-WSSV 10^-4 with 60.00% mortality. Treatment with higher concentration of WSSV infection hadhigher mortality than that with lower concentration of WSSV infection under the same condition. Meanwhile, the amount of WSSV determined by Real-time Relative PCR showed that the stress of NO2-N accelerated WSSV proliferation in shrimp gills. The WSSV quantity of 10^-4 stress group was 1.33 times that of stress-free group at 48 h while it reached 2.00 times at 72 h. In addition, immunity-related enzymes activity experiment showed that the activities of phenoloxidase （PO）, acid phosphatase （ACP） and alkaline phosphatase （AKP） in shrimp serum elevated first and then declined with time prolonged under stress of NO2-N. This study indicated that synergy of NO2-N accelerated WSSV proliferation in WSSV-infected shrimp and caused higher mortality, because environment stress lowered the activities of immune-related enzymes and the ability of anti-infection of shrimp.

关 键 词：凡纳滨对虾 WSSV 胁迫 亚硝基氮 致病性 

分 类 号：S945[农业科学—水产养殖]